15 Best Size 8 Smart Rings, Compared
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Choosing the best Size 8 smart rings requires comparing strict specifications rather than relying on hype. We analyzed 15 models to find the right fit for your needs. The OURA Ring 5 Size 8 Silver leads this list because its 0.09-inch width offers a minimalist profile for detailed health tracking. Our picks are based solely on the specifications published on the listings. This guide helps you decide which device matches your priorities for battery life, materials, and tracking features.
Check case material and battery life
Most Size 8 smart rings use titanium for durability, while others use standard metals. Battery life varies significantly. Some models offer seven days, while others last up to 35 days. You should match the battery capacity to your charging habits. Titanium builds provide longer life and sturdiness. Choose based on whether you prefer daily charging or weekly convenience.
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | OURA Ring 5 Size 8 Silver Best overall | minimalist design and detailed health tracking | |
| 2 | RingConn Gen 3 Size 8 Rose Gold Best vibration alerts | discreet vibration alerts and vascular trends | |
| 3 | RingConn Gen 2 Air Size 8 Also great | Users seeking ultra-thin comfort and long battery life | |
| 4 | Oura Ring 4 Size 8 Stealth Also great | screen-free health tracking and sleep analysis | |
| 5 | RingConn Gen 2 Size 8 Smart Ring Also great | sleep apnea monitoring and long battery life | |
| 6 | OURA Ring 4 Rose Gold Size 8 Also great | women seeking detailed health metrics and long battery life | |
| 7 | Femometer Ring Air Size 8 Best budget | lightweight women's sleep and cycle tracking | |
| 8 | Samsung Galaxy Ring Size 8 Titanium Best premium | Android users wanting a titanium build | |
| 9 | RENPHO Lynx Size 8 Smart Ring Best black | subscription-free titanium health tracking | |
| 10 | femometer Ring Gen2 Size 8 Also great | women seeking cycle tracking via BBT | |
| 11 | POBOVi Gen2 Titanium Smart Ring Size 8 Best spo2 | SpO2 monitoring and subscription-free health data | |
| 12 | Oura Ring Gen3 Horizon Size 8 Silver Also great | users needing deep biometric data and app integration | |
| 13 | Ultrahuman Ring PRO Size 8 Also great | Subscription-free titanium health tracking | |
| 14 | Oura Ring 5 Size 8 Gold Also great | advanced health tracking in a compact titanium design | |
| 15 | Amazfit Helio Titanium Smart Ring Size 8 Also great | detailed health tracking without subscription fees |
The best fit for you
- You want the most compact model on the list – OURA Ring 5 Size 8 Silver – It weighs 2.12 ounces with a 0.09-inch width, making it the lightest and thinnest option.
- You need discreet vibration alerts for notifications – RingConn Gen 3 Size 8 Rose Gold – This ring includes vibration alerts and offers vascular insights without requiring a subscription.
- You want a durable titanium build for Android – Samsung Galaxy Ring Size 8 Titanium – It features a titanium case, seven-day battery life, and works with Android devices.
OURA Ring 5 Size 8 Silver
Best for: minimalist design and detailed health tracking
- Size
- Size 8
- Battery Life
- 1 week
- Subscription
- Oura Membership
- Tracked Metrics
- Sleep, activity, stress, heart health
- Case Material
- Titanium
- Water Resistance
- IP68
The Oura Ring 5 is the world’s smallest smart ring, measuring 0.09 inches wide and 0.24 inches long. It weighs 2.12 ounces and features a scratch-resistant titanium case. This Size 8 model tracks sleep, activity, stress, and heart health with research-grade accuracy. It offers one week of battery life and IP68 water resistance. You will need the dedicated app for data access.
- Titanium case is 40% smaller than previous generation
- Tracks over 50 health metrics including women's health
- Integrates with over 40 apps like Strava
- IP68 water resistance for daily wear
- Requires a paid subscription after the first month
- Uses unique sizing different from standard jewelry rings
- Weighs 2.12 ounces which may feel substantial
- You want the thinnest possible smart ring profile
- You need detailed women's health tracking metrics
- You prefer a scratch-resistant titanium build
- You refuse to pay a monthly subscription fee
- You want a ring that fits like standard jewelry
- You need battery life longer than one week
Verdict: OURA Ring 5 Size 8 Silver is the most compact option for users prioritizing minimal size and deep health insights. It fits you if you accept the subscription model for access to your data.
RingConn Gen 3 Size 8 Rose Gold
Best for: discreet vibration alerts and vascular trends
- Size
- Size 8
- Battery Life
- Up to 14 days
- Tracked Metrics
- Sleep, heart rate, HRV, stress, SpO2
- Water Resistance
- IP68
- Ring Size
- Size 8
- Features
- Vibration Alerts
The RingConn Gen 3 offers vascular health insights and vibration alerts in a Size 8 ring. It tracks sleep, heart rate, HRV, stress, and SpO2 without subscription fees. Battery life lasts up to 14 days with IP68 water resistance. This model suits you if you want discreet haptic feedback and long wear time. The brushed rose gold finish and 0.09-inch height provide a comfortable fit for daily use.
- Vibration alerts for discreet notifications
- Up to 14 days battery life
- No subscription fees for app access
- IP68 water resistance rating
- 0.09-inch height is thicker than ultra-thin competitors
- Vibration alerts reduce maximum battery duration
- You want discreet vibration alerts
- You prefer no subscription fees
- You need vascular health trend data
- You require an ultra-thin profile
- You want a black color option
- You need AI health features
Verdict: RingConn Gen 3 Size 8 Rose Gold delivers vascular insights and vibration alerts with 14-day battery life. It fits you if you value haptic feedback and subscription-free tracking over a slim profile.
RingConn Gen 2 Air Size 8
Best for: Users seeking ultra-thin comfort and long battery life
- Size
- Size 8
- Battery Life
- Up to 10 days
- Compatibility
- iOS & Android
- Subscription
- No subscription fee
- Tracked Metrics
- Sleep, heart rate, stress, blood oxygen
- Water Resistance
- IP68
The RingConn Gen 2 Air is an ultra-thin smart ring designed for comfort during sleep and daily activity. It features a slim 2mm profile and weighs just 2.5g. You get up to 10 days of battery life on a single charge. The device tracks sleep, heart rate, stress, and blood oxygen. It supports iOS and Android and includes an AI assistant for health insights. This size 8 model is HSA/FSA eligible.
- Ultra-thin 2mm profile for comfortable wear
- Lightweight 2.5g construction
- Up to 10 days of battery life
- IP68 waterproof rating for swimming and diving
- No subscription fee for standard features
- Requires a separate sizing kit for accurate fit
- Uses unique sizing standards different from standard ring sizes
- You want a lightweight ring that does not feel bulky
- You need long battery life between charges
- You want to use HSA or FSA funds
- You prefer standard ring sizing without a kit
- You need a ring with a larger battery life
- You want a ring that does not require an app for basic tracking
Verdict: RingConn Gen 2 Air Size 8 fits users who prioritize a barely-there feel and extended battery life over standard sizing convenience. It is a practical option for those willing to use a sizing kit for a precise fit.
Oura Ring 4 Size 8 Stealth
Best for: screen-free health tracking and sleep analysis
- Size
- Size 8
- Battery Life
- Up to 8 days
- Compatibility
- Android & iOS
- Subscription
- Monthly membership
- Tracked Metrics
- Sleep, activity, stress, heart health
- Ring Size
- Size 8
The Oura Ring 4 in Size 8 offers continuous health tracking without a screen. It measures sleep, activity, stress, and heart health using Smart Sensing. The device provides up to 8 days of battery life. It includes women’s health metrics and an AI advisor. You need a monthly membership to access data after the first free month. It works with iOS and Android devices.
- Tracks over 50 health metrics including sleep and stress
- Up to 8 days of battery life
- Smart Sensing adapts data to your body
- Includes women’s health tracking features
- HSA and FSA eligible
- Monthly subscription required after the first month
- Weight of 6.35 ounces is high for a ring
- Requires specific sizing kit for accurate fit
- You want detailed sleep and activity metrics
- You prefer a screen-free wearable design
- You need women's health tracking capabilities
- You want to avoid a monthly subscription fee
- You prefer a lighter ring under 6 ounces
- You need standard jewelry ring sizing
Verdict: The Oura Ring 4 Size 8 Stealth is a solid choice for users who prioritize comprehensive health data and long battery life. It suits those who do not mind a subscription model for continuous insights.
RingConn Gen 2 Size 8 Smart Ring
Best for: sleep apnea monitoring and long battery life
- Size
- Size 8
- Battery Life
- Up to 10-12 days
- Compatibility
- Android, iOS
- Tracked Metrics
- Sleep apnea, HR, HRV, SpO2, stress
- Water Resistance
- Up to 100 m
- Ring Size
- Size 8
The RingConn Gen 2 in Size 8 is a lightweight smart ring weighing 2 grams with an ultra-thin design. It tracks sleep apnea, heart rate, HRV, and blood oxygen saturation. The device offers 10 to 12 days of battery life and supports 100 m water resistance. It works with Android and iOS without requiring a subscription. This ring suits users seeking sleep apnea insights and long battery endurance.
- Tracks sleep apnea with real-time AHI data
- 10 to 12 days of battery life
- 100 m water resistance for swimming
- No subscription fees for app access
- Weighs just 2 grams
- Battery life is lower than some competitors offering 15+ days
- Sleep apnea tracking may require additional setup compared to basic heart rate monitors
- Unique sizing standards differ from U.S. norms requiring a kit
- You want detailed sleep apnea monitoring
- You prefer a ring with no monthly subscription fees
- You swim regularly and need 100 m water resistance
- You need a ring with over 15 days of battery life
- You prefer standard U.S. ring sizing without a kit
- You only need basic step counting and heart rate tracking
Verdict: The RingConn Gen 2 Size 8 Smart Ring fits users who prioritize sleep apnea data and long battery life. It offers a lightweight, subscription-free experience for swimmers and sleep trackers.
OURA Ring 4 Rose Gold Size 8
Best for: women seeking detailed health metrics and long battery life
- Size
- Size 8
- Battery Life
- Up to 8 days
- Compatibility
- Android & iOS
- Subscription
- Monthly membership
- Tracked Metrics
- Sleep, activity, stress, heart health
- Ring Size
- Size 8
The Oura Ring 4 in Size 8 offers continuous health tracking for sleep, activity, and stress. It features Smart Sensing technology to adapt to your body and includes specific women’s health metrics. The battery lasts up to 8 days on a single charge. This model is designed for Android and iOS users. It suits those who want detailed physiological data without a screen.
- Tracks over 50 health metrics including sleep and heart health
- Up to 8 days of battery life
- Smart Sensing adapts data accuracy to your body
- Includes women’s health tracking features
- Requires a monthly subscription after the first free month
- Battery life is lower than the 10-day capacity of some competitors
- Physical dimensions of 1.02 by 0.31 inches are bulkier than ultra-thin alternatives
- You want detailed women’s health tracking data
- You prefer a ring without a screen or vibrations
- You need compatibility with both Android and iOS
- You want to avoid a recurring monthly membership fee
- You prefer an ultra-thin ring profile under 0.30 inches
- You do not need women’s health specific metrics
Verdict: OURA Ring 4 Rose Gold Size 8 is a solid choice for women seeking comprehensive health insights via Smart Sensing and long battery life, provided you accept the subscription requirement.
Femometer Ring Air Size 8
Best for: lightweight women's sleep and cycle tracking
- Size
- Size 8
- Tracked Metrics
- Heart rate, blood oxygen, sleep, stress
- Water Resistance
- IP68
- Ring Size
- Size 8
- Target Audience
- Women
- Tracking Features
- Heart Rate Monitoring, Blood Oxygen, Women's Health Tracking
The Femometer Ring Air is a Size 8 smart ring designed for women. It weighs 3.3g with a 7mm profile for all-day comfort. The device tracks heart rate, blood oxygen, sleep, and stress. It includes triple-temperature sensors for basal body temperature monitoring. You get up to 30 days of battery life. The IP68 waterproof rating supports daily wear and workouts. No subscription is required for the app.
- Ultra-lightweight 3.3g build
- 30-day battery life
- Triple-temperature sensors
- IP68 waterproof rating
- No subscription required
- Smaller 7mm profile limits sensor surface area
- Lighter 3.3g weight may reduce durability perception
- Limited tracked metrics compared to competitors
- You want a lightweight ring for sleep tracking
- You need women's health insights like BBT
- You prefer no monthly subscription fees
- You require advanced stress analysis tools
- You need comprehensive blood pressure monitoring
- You prefer a heavier, more robust build
Verdict: Femometer Ring Air Size 8 fits women seeking lightweight sleep and cycle tracking without subscription fees. It suits those prioritizing comfort and battery life over advanced metrics.
Samsung Galaxy Ring Size 8 Titanium
Best for: Android users wanting a titanium build
- Size
- Size 8
- Battery Life
- Up to 7 days
- Compatibility
- Android only
- Tracked Metrics
- Heart rate, sleep, cycle, temperature
- Case Material
- Titanium
- Water Resistance
- Water-resistant
The Samsung Galaxy Ring in Size 8 is an Android-only smart ring built from titanium. It tracks heart rate, sleep, cycle, and temperature while offering up to 7 days of battery life. The concave design minimizes scratches, and it is water-resistant for daily wear. It requires no app subscription for basic insights. This ring suits Android users seeking a durable, lightweight fitness tracker that fits comfortably during sleep and exercise.
- Titanium case for durability
- Up to 7 days battery life
- Tracks heart rate, sleep, cycle, and temperature
- Water-resistant design
- No app subscription required
- Limited to Android smartphones only
- 7-day battery life is shorter than some competitors
- Concave design may collect debris in grooves
- You use an Android smartphone
- You want a titanium build
- You prefer no subscription fees
- You use an iPhone
- You need iOS compatibility
- You want a wider color selection
Verdict: Samsung Galaxy Ring Size 8 Titanium is a practical choice for Android users who want a durable, subscription-free tracker. It fits best if you prioritize a titanium build and seamless integration with your phone.
RENPHO Lynx Size 8 Smart Ring
Best for: subscription-free titanium health tracking
- Size
- Size 8
- Battery Life
- 7 days
- Compatibility
- iOS and Android
- Subscription
- No subscription fees
- Tracked Metrics
- Sleep, blood oxygen, stress, heart rate
- Case Material
- Titanium
The RENPHO Lynx in Size 8 is a titanium smart ring designed for all-day wear. It tracks sleep, blood oxygen, stress, and heart rate without requiring a subscription. The device features a 7-day battery life and includes a charging case for convenient power management. With 5ATM water resistance, it handles swimming and daily activities. This model suits users seeking straightforward health metrics and a durable, subscription-free tracking experience.
- Titanium exterior for durable 24/7 wear
- No subscription fees required for app access
- Includes a charging case for extra power and storage
- 5ATM water resistance for swimming and hiking
- 7-day battery life is lower than the 10-day life found in the RingConn Gen 2 Air
- 0.12-inch height is thicker than the ultra-thin designs of the femometer Ring Air
- Tracks only sleep, blood oxygen, stress, and heart rate, excluding vascular trends or sleep apnea monitoring
- You want a subscription-free health tracking experience
- You need a durable titanium ring for swimming and outdoor activities
- You prefer a charging case for convenient travel storage
- You require ultra-thin design profiles under 0.12 inches
- You need advanced medical monitoring like sleep apnea detection
- You want a battery life exceeding 7 days on a single charge
Verdict: The RENPHO Lynx Size 8 Smart Ring fits users who prioritize durable titanium construction and a no-subscription model over ultra-thin designs or extended battery life.
femometer Ring Gen2 Size 8
Best for: women seeking cycle tracking via BBT
- Size
- Size 8
- Compatibility
- iOS, Android
- Tracked Metrics
- Heart rate, HRV, SpO2, sleep, BBT
- Case Material
- Ceramic exterior, aluminum core
- Water Resistance
- Up to 100 m
- Ring Size
- Size 8
The femometer Ring Gen2 in Size 8 is a smart ring built for women. It tracks heart rate, HRV, sleep stages, and blood oxygen. Its key spec is advanced basal body temperature monitoring for cycle tracking. The device weighs 3.3 grams with a 35-day battery life. It pairs with a free app on iOS and Android. This ring suits those prioritizing women’s health metrics in a lightweight design.
- 35-day battery life with charging case
- 1,400+ nightly BBT measurements for cycle tracking
- 3.3g weight and 2.7mm thickness
- Lifetime free femometer app subscription
- 100m water resistance
- 3.3g weight is heavier than ultra-thin competitors
- 35-day battery life is lower than 10-day average models
- Targeted primarily at women with specific cycle features
- You want detailed cycle and ovulation tracking via BBT
- You prefer a lightweight ring under 4 grams
- You need a subscription-free health tracking app
- You require sleep apnea medical monitoring
- You need a ring lighter than 3 grams
- You prefer a ring with over 10 days of continuous single-charge use without a case
Verdict: The femometer Ring Gen2 Size 8 fits women who value precise basal body temperature data for cycle tracking. Its 35-day battery and free app make it a practical long-term health companion.
POBOVi Gen2 Titanium Smart Ring Size 8
Best for: SpO2 monitoring and subscription-free health data
- Size
- Size 8
- Battery Life
- 5-7 days
- Compatibility
- iOS & Android
- Tracked Metrics
- Sleep, heart rate, stress, SpO2
- Case Material
- Titanium
- Water Resistance
- IP68
The POBOVi Gen2 is a titanium smart ring in Size 8 that tracks heart rate, SpO2, stress, and sleep breathing rate. It offers 5-7 days of battery life and features IP68 water resistance up to 100 meters. The device works with iOS and Android. It includes a free health subscription with no recurring fees. This ring suits users who want precise health monitoring and long battery performance in a durable titanium build.
- Titanium case for durable, lightweight wear
- 5-7 days battery life per charge
- IP68 waterproof up to 100 meters
- Tracks SpO2 and sleep breathing rate
- No subscription fees for health data
- Battery life is lower than some competitors offering 10+ days
- Uses a proprietary sizing system requiring a specific kit
- Smaller battery capacity limits usage compared to thicker rings
- You want a durable titanium ring for daily health tracking
- You prefer a device with no monthly subscription fees
- You need reliable SpO2 and sleep breathing rate monitoring
- You want a ring with a 10-day or longer battery life
- You prefer standard ring sizes without a separate sizing kit
- You need advanced sleep apnea diagnosis features
Verdict: The POBOVi Gen2 Titanium Smart Ring Size 8 is a solid choice for users prioritizing a durable titanium build and accurate SpO2 tracking without subscription costs. It fits those who value long battery life and specific health insights like breathing rate.
Oura Ring Gen3 Horizon Size 8 Silver
Best for: users needing deep biometric data and app integration
- Size
- Size 8
- Battery Life
- 5-7 days
- Compatibility
- iOS and Android
- Subscription
- Monthly membership
- Tracked Metrics
- Sleep, activity, stress, heart rate
- Ring Size
- Size 8
The Oura Ring Gen3 Horizon in Size 8 is a sleep and activity tracker with research-grade sensors. It monitors heart rate, stress, and sleep metrics with precision. The device offers a 5-7 day battery life and syncs with over 40 apps on iOS and Android. It includes a sizing kit for accurate fitting. This ring suits users seeking detailed biometric data integration with their existing health apps.
- Research-grade sensors monitor over 20 biometrics
- Syncs with over 40 apps including Apple Health
- 5-7 day battery life
- Includes Gen3 Sizing Kit for accurate fit
- Requires a monthly subscription for full access
- 5-7 day battery life is lower than some competitors
- Width of 0.91 inches is bulkier than ultra-thin alternatives
- You want detailed sleep and activity insights
- You need compatibility with Apple Health or Strava
- You prefer a ring with a sizing kit included
- You want a subscription-free app experience
- You prefer a thinner ring profile under 0.30 inches
- You want a device that does not require a membership
Verdict: Oura Ring Gen3 Horizon Size 8 Silver delivers precise biometric tracking and broad app compatibility. It fits users who prioritize data depth and integration over battery longevity or a subscription-free model.
Ultrahuman Ring PRO Size 8
Best for: Subscription-free titanium health tracking
- Size
- Size 8
- Battery Life
- Up to 15 days
- Compatibility
- iPhone, Android
- Tracked Metrics
- Sleep, recovery, heart rate, HRV
- Case Material
- Titanium
- Water Resistance
- 100 m
The Ultrahuman Ring PRO in Size 8 is a titanium smart ring designed for tracking sleep, recovery, and heart rate. It offers up to 15 days of battery life per charge and stores up to 250 days of data locally. The device is water-resistant to 100 meters and works with iPhone and Android. It requires no monthly subscription for the app, making it a practical option for users seeking long-term health insights without recurring fees.
- Titanium case construction for durability
- Up to 15 days battery life
- No mandatory monthly subscription fee
- Water-resistant to 100 meters
- Stores up to 250 days of data
- Battery life is shorter than the 45-day total potential of the charging case system
- Weighs up to 4.8 grams depending on size, which is heavier than ultra-thin alternatives
- You want a subscription-free health tracking ring
- You need water resistance for swimming
- You prefer a titanium build over plastic
- You need a ring lighter than 3.3 grams
- You require a battery life exceeding 15 days without the case
Verdict: The Ultrahuman Ring PRO Size 8 fits users who prioritize long battery life and a durable titanium build without paying a monthly fee. It is a solid choice for swimmers and those who value data storage over ultra-lightweight wearability.
Oura Ring 5 Size 8 Gold
Best for: advanced health tracking in a compact titanium design
- Size
- Size 8
- Battery Life
- 6-9 days
- Subscription
- Monthly membership
- Tracked Metrics
- Sleep, activity, stress, heart health
- Case Material
- Titanium
- Water Resistance
- IP68
The Oura Ring 5 in Size 8 is a titanium smart ring that tracks sleep, activity, and heart health. It measures 40% smaller than the previous generation and offers 6 to 9 days of battery life. This model includes a monthly membership for app access. It suits users who want a lightweight, scratch-resistant device with research-grade sensors for daily health monitoring.
- Titanium case is 40% smaller than the previous generation
- 6 to 9 days of battery life
- Tracks over 50 health metrics including sleep and stress
- IP68 water resistance rating
- Requires a monthly subscription for full app access
- Heavier at 2.12 ounces compared to ultra-thin competitors
- Unique sizing requires a specific sizing kit
- You want a smaller, scratch-resistant titanium ring
- You need detailed sleep and heart health metrics
- You are comfortable with a monthly membership fee
- You prefer a subscription-free app experience
- You want a ring lighter than 2.12 ounces
- You need standard jewelry ring sizing
Verdict: Oura Ring 5 Size 8 Gold is a compact, durable option for users who prioritize advanced health metrics and a smaller form factor over a subscription-free model.
Amazfit Helio Titanium Smart Ring Size 8
Best for: detailed health tracking without subscription fees
- Size
- Size 8
- Compatibility
- iOS, Android
- Tracked Metrics
- Heart rate, SpO2, HRV, sleep, stress
- Case Material
- Titanium alloy
- Water Resistance
- Water-resistant
- Ring Size
- Size 8
The Amazfit Helio is a titanium alloy smart ring in Size 8. It tracks heart rate, blood oxygen, HRV, sleep, and stress. The device is water-resistant and works with iOS and Android. It includes VO2 Max data via the Zepp App. You get full health assessments without a subscription. This ring suits users who want detailed metrics and a durable build.
- Titanium alloy case for lightweight comfort
- Tracks heart rate, SpO2, HRV, and sleep
- Includes EDA sensor for stress management
- No subscription required for full features
- Water-resistant design for daily wear
- Unique sizing does not match standard jewelry sizes
- Requires Helio Ring Sizing Kit for correct fit
- Width is 1.01 inches, which is bulkier than ultra-thin alternatives
- You want comprehensive health metrics like VO2 Max
- You prefer a durable titanium alloy build
- You want full features without a monthly fee
- You need a ring that fits standard jewelry sizes
- You prefer an ultra-thin profile under 1 inch
- You want a device that does not require a separate sizing kit
Verdict: Amazfit Helio Titanium Smart Ring Size 8 offers robust health tracking in a durable titanium build for users who prioritize detailed metrics and do not mind a specialized sizing process.
Specifications side by side
| Spec | OURA Ring 5 Size 8 Silver | RingConn Gen 3 Size 8 Rose Gold | RingConn Gen 2 Air Size 8 | Oura Ring 4 Size 8 Stealth | RingConn Gen 2 Size 8 Smart Ring | OURA Ring 4 Rose Gold Size 8 | Femometer Ring Air Size 8 | Samsung Galaxy Ring Size 8 Titanium | RENPHO Lynx Size 8 Smart Ring | femometer Ring Gen2 Size 8 | POBOVi Gen2 Titanium Smart Ring Size 8 | Oura Ring Gen3 Horizon Size 8 Silver | Ultrahuman Ring PRO Size 8 | Oura Ring 5 Size 8 Gold | Amazfit Helio Titanium Smart Ring Size 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Battery Life | 1 week | Up to 14 days | Up to 10 days | Up to 8 days | Up to 10-12 days | Up to 8 days | – | Up to 7 days | 7 days | – | 5-7 days | 5-7 days | Up to 15 days | 6-9 days | – |
| Compatibility | – | – | iOS & Android | Android & iOS | Android, iOS | Android & iOS | – | Android only | iOS and Android | iOS, Android | iOS & Android | iOS and Android | iPhone, Android | – | iOS, Android |
| Subscription | Oura Membership | – | No subscription fee | Monthly membership | – | Monthly membership | – | – | No subscription fees | – | – | Monthly membership | – | Monthly membership | – |
| Tracked Metrics | Sleep, activity, stress, heart health | Sleep, heart rate, HRV, stress, SpO2 | Sleep, heart rate, stress, blood oxygen | Sleep, activity, stress, heart health | Sleep apnea, HR, HRV, SpO2, stress | Sleep, activity, stress, heart health | Heart rate, blood oxygen, sleep, stress | Heart rate, sleep, cycle, temperature | Sleep, blood oxygen, stress, heart rate | Heart rate, HRV, SpO2, sleep, BBT | Sleep, heart rate, stress, SpO2 | Sleep, activity, stress, heart rate | Sleep, recovery, heart rate, HRV | Sleep, activity, stress, heart health | Heart rate, SpO2, HRV, sleep, stress |
| Case Material | Titanium | – | – | – | – | – | – | Titanium | Titanium | Ceramic exterior, aluminum core | Titanium | – | Titanium | Titanium | Titanium alloy |
| Water Resistance | IP68 | IP68 | IP68 | – | Up to 100 m | – | IP68 | Water-resistant | 5ATM | Up to 100 m | IP68 | – | 100 m | IP68 | Water-resistant |
| Ring Size | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 |
| Target Audience | Women | – | Women | Women | Women | Women | Women | – | – | Women | – | – | Women | Women | – |
| Features | Sleep Tracking | Vibration Alerts | – | – | – | – | – | Sleep Tracking | – | – | SpO2 | Sleep Tracking | – | Sleep Tracking | – |
| Color | Silver | Brushed Rose Gold | Dune Gold | Stealth | Future Silver | Rose Gold | Rose Gold | Gold | Black | Gold | Matte Silver | Silver | Aster Black | Gold | Silver |
| Size | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 | Size 8 |
| Tracking Features | Women's Health Tracking | Heart Rate Monitoring | Heart Rate Monitoring | Women's Health Tracking | Heart Rate Monitoring, Women's Health Tracking | Women's Health Tracking | Heart Rate Monitoring, Blood Oxygen, Women's Health Tracking | – | – | Heart Rate Monitoring, Women's Health Tracking | Heart Rate Monitoring | Heart Rate Monitoring | Heart Rate Monitoring | Women's Health Tracking | Heart Rate Monitoring |
| Length | 0.24 inches | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| Width | 0.09 inches | – | – | – | – | – | – | – | – | – | – | – | – | – | – |
| Weight | 2.12 ounces | – | – | 6.35 ounces | – | – | – | – | – | – | – | – | – | 2.12 ounces | – |
| Dimensions | – | 0.87 × 0.87 × 0.09 inches | 11.3 × 4.3 × 4.7 inches | 0.91 × 0.91 × 0.31 inches | 11.3 × 4.3 × 4.7 inches | 1.02 × 1.02 × 0.31 inches | – | 2.07 × 0.92 × 0.72 inches | 0.71 × 0.71 × 0.12 inches | – | – | 0.91 × 0.91 × 0.31 inches | – | – | 1.01 × 1.01 × 0.31 inches |
| Model | JZ90-61403-08 | RCA-03 | RCA-02 | JZ90-54218-08 | RCA-01 | ORRGTISZ8 | – | SM-Q508NZDAXAR | R-MZW01 | 42616f15-b2f2-4c4a-9129-287f3771f45c | – | JZ90-51384-08 | – | – | W2321TY2N |
If you manage room automation, you can compare the best smart home controllers with 8 Zones by their technical specifications.
How to choose the right size 8 smart ring
Check subscription requirements
You must decide if you want to pay a monthly fee for your data. The OURA Ring 5 and OURA Ring 4 models require a subscription to access detailed health insights. In contrast, the RingConn Gen 3 and Samsung Galaxy Ring offer tracking without any recurring costs. If you prefer owning your data outright, look for the No Subscription attribute. This choice affects your long-term ownership cost and privacy, so verify the model's specific terms before buying.
Evaluate case materials
The build material impacts durability and weight. Titanium is a common choice for premium models like the Samsung Galaxy Ring and the RENPHO Lynx, offering high strength and corrosion resistance. Other rings use standard metals or coatings. Titanium models often feel more substantial. You should check the Case Material attribute to see if you prefer the lightweight feel of titanium or the specific finish of other metals. This affects how the ring feels during daily wear and exercise.
Review battery longevity
Battery life determines how often you charge your device. The femometer Ring Gen2 offers up to 35 days of use, which is significantly longer than the standard seven-day battery found in the Samsung Galaxy Ring and Oura Ring Gen3. Longer battery life reduces maintenance. You should compare the Battery Life attribute for each model. If you travel frequently or dislike charging habits, prioritize models with extended endurance. Shorter battery life may require more frequent charging routines.
Identify tracking features
Different rings focus on specific health metrics. The RingConn Gen 2 provides sleep apnea monitoring, while the Femometer Ring Air focuses on women's health and cycle tracking. The POBOVi Gen2 highlights SpO2 monitoring. You should match the Tracking Features attribute to your personal health goals. If you need sleep apnea data, choose RingConn. If you want cycle tracking, consider Femometer. Do not assume all rings track the same metrics. Verify the specific sensors and algorithms listed for each device.
Confirm device compatibility
You must ensure the ring works with your smartphone. Most models, including the RingConn Gen 2 and Amazfit Helio, support both Android and iOS. However, the Samsung Galaxy Ring is optimized for Android users. You should check the Compatibility attribute before purchasing. If you use an iPhone, avoid Samsung models. If you use Android, you have broader options. Verify this early to avoid buying a device that cannot sync with your phone.
Frequently asked questions
Do all Size 8 smart rings require a monthly subscription?
No, not all models require a subscription. The RingConn Gen 3, RingConn Gen 2 Air, and Samsung Galaxy Ring provide data without a monthly fee. In contrast, the OURA Ring 5 and OURA Ring 4 require a subscription to access detailed health insights. You should check the specific model's attributes to confirm if ongoing costs apply to your chosen device.
Which Size 8 ring is best for women's health tracking?
Several models support women's health tracking, including the OURA Ring 5, OURA Ring 4, RingConn Gen 2, and Femometer Ring Air. The Femometer Ring Gen2 focuses specifically on basal body temperature for cycle tracking. The OURA Ring 4 Rose Gold also targets women with detailed metrics. You should select a model that explicitly lists Women's Health Tracking in its attributes.
How long does the battery last on these rings?
Battery life varies by model. The Samsung Galaxy Ring and RENPHO Lynx offer a 7-day battery life. The femometer Ring Gen2 provides up to 35 days of battery. The RingConn Gen 3 delivers 14 days of battery life. You should match the battery capacity to your charging habits to ensure uninterrupted tracking during your daily routine.
Are these rings waterproof for swimming?
Some models are water-resistant, while others do not specify this feature. The OURA Ring 5 and Femometer Ring Air both carry an IP68 Waterproof rating. This allows you to wear them during hand washing or light swimming. You should verify the water resistance rating in the attributes before purchasing if you plan to use the ring during aquatic activities.
Which Size 8 ring has the thinnest profile?
The OURA Ring 5 Size 8 Silver is the most compact option with a 0.09-inch width. The RingConn Gen 3 also features a slim 0.09-inch height. The RENPHO Lynx has a 0.12-inch height. You should compare the width and height specifications to determine which form factor fits your comfort preferences and daily wear style.
Can I use these rings with both Android and iOS?
Most models support both platforms. The RingConn Gen 2 Air, OURA Ring 4, RingConn Gen 2, and Amazfit Helio Titanium are compatible with Android and iOS. The Samsung Galaxy Ring is optimized for Android users. You should check the compatibility attributes to ensure the ring works with your specific phone operating system.
See also
- 12 Best Smart Rings with iOS, Compared
- Best Smart Rings with Android: 12 Spec-Based Picks
- Best Smart Rings with Heart Rate Monitoring in 2026: 12 Picks Ranked by Specs
- 13 Best Smart Rings with No Subscription, Compared
- Best Silver Smart Rings: 13 Spec-Based Picks
- Best Smart Rings for Women in 2026: 14 Picks Ranked by Specs